A bomb has been detonated in Istanbul targeting police near the headquarters of Turkey’s ruling AK Party.

Authorities say 15 officers and a civilian were injured after the device was triggered by remote control as a police bus passed by.

Istanbul’s governor said the bomb contained plastic explosive. Police sources said it had been hidden on a motorbike at a road junction.

One eyewitness told euronews: “I was in a minibus, and as we were driving alongside the police van we heard the explosion. I saw the tyres blow out. I saw the blast and felt a strong impact from the explosion. We stopped and ran back to find the injured policemen.”

So far, no one has claimed the attack, though Kurdish separatists, Islamist militants – including al-Qaeda – and extreme left- and right-wing groups have all carried out attacks in Turkey.

Our correspondent in Istanbul, Bora Bayraktar, said: “The police van continued a further 100 metres after the explosion. Investigators are searching the vehicle for clues about the attackers.”